不同部位缺血预处理对未成熟心肌保护作用的研究

Experimental Study of Different Sites Ischemic Preconditioning on Immature Cardioprotection

目的探讨不同部位缺血预处理对未成熟心肌保护作用。方法采用经典心脏缺血预处理、肾缺血预处理及双下肢缺血预处理动物Langendorff灌注模型比较三种方法对缺血 /再灌(I/R)未成熟心肌损伤的效应。分为5组 :正常对照组(NC,n=6) ,离体心脏仅灌注KH液70min;缺血 /再灌 (I/R ,n=6) ,离体心脏灌注15min转为工作心15min后停灌45min,恢复灌注15min改为工作心30min;心脏缺血预处理组 (IPC,n=6),离体心脏灌注15min转为工作心15min后反复2次缺血5min/再灌5min,然后重复I/R组方法 ;肾缺血预处理组(K -IPC ,n=6) ,反复3次阻断左肾动脉5min,放开5min,然后重复I/R组方法。双下肢缺血预处理组 (DL-IPC ,n=6) ,反复3次捆扎双下肢5min,松开5min,然后重复I/R组方法。以左心室功能恢复、心肌含水量、血清肌酸激酶 (CK)和乳酸脱氢酶 (LDH)漏出率 ,心肌组织ATP和丙二醛 (MDA)含量、超氧化物歧化酶(SOD)活性及电镜作为观察指标。结果IPC、DL-IPC及K-IPC组在左心室功能恢复优于I/R组 (P<0.05) ,在ATP含量、SOD活性及心肌超微结构方面均优于I/R组(P<0.01) ,心肌含水量低于I/R组 (P<0.05) ,在MDA含量、CK、LDH漏出率方面均低于I/R组 (P<0.01)。结论不同部位的非心脏缺血预处理 。

Objective To determine the effect of different sites ischemic preconditioning on immature myocardial protection.Methods Isolated perfused neonatal rabbit hearts from ischemic_reperfusion group (I/R), ischemic preconditioning(IPC)group,kidney ischemic preconditioning (K_IPC) group and double limbs_ ischemic perconditioning(DL-IPC) group underwent 45_minute ischemia followed by 45_minute reperfusion before I/R group without IPC, IPC group with 2× IPC(5_minute ischemia followed by 5_minute reperfusion), K_IPC group with 3×IPC(left kidney artery was clamped for 5minutes followed by 5_minute reperfusion),group DL_IPC with 3×IPC(double limbs were obstructed for 5_minute followed by 5_minute reperfusion),but normal controll(NC) without ischemia was only perfused KH solution for 70minutes. The left ventricular function recovery, MWC,LDH and CK leakage,MDA and ATP content and SOD activity were tested.Results The recovery of postischemic heart function,ATP content,SOD activity in IPC,DL_IPC and K_IPC group were higher than those in I/R group. MWC, MDA content, LDH and CK leakage in IPC,DL_IPC and K_IPC groups were lower than those in I/R group.Conclusions DL_IPC and K_IPC had the same cardioprotection to immature myocardium as IPC.